Dawn, I don't know about fatalities, but there is one set of tests done by a canyoneering group and another set by a rescue group that indicates that falls onto dyneema (such as one might take while tethered to a rappel anchor) produce forces in excess of the UIAA maximum limit and in some cases are enough to break the dyneema sling.
I have no problem believing that but that's a very different subject.
I was following, to some extent, the discussions on rockclimbing.com and am one of those people not too concerned about the pieces being loaded sequentially rather than simultaneously, especially at the Gunks. I thought from the tone of the original post that some kind of real world accident had ensued which might cause me to re-evaluate my position. As long as it's still just geeks arguing equations, I'm OK with what I'm doing.